| To understand the role of caustic addition and its effect on the bitumen extraction process, a novel flow cell and a Denver Cell extraction unit were utilized. This allowed for the comparison of sodium hydroxide and ammonium hydroxides effect on real oil sands ores. Several ores (A1, C-ore, SunP210) were tested at various pH levels in process water that was adjusted by either the sodium hydroxide or ammonium hydroxide.;The novel flow cell allowed for viewing of the liberation process which showed that both caustics performed similarly in all cases. In the overall recovery, ammonium hydroxide increased the percent recovered greatly at the high pH of 11.3. This was due to several factors such as smaller induction times, a more hydrophobic bitumen surface, less negative zeta potentials and a decrease in the release of natural surfactants in ammonium hydroxide solutions. Overall, ammonium hydroxide was found to be a suitable replacement for sodium hydroxide. |
